1. Field of the Invention
The invention relates to a stair climbing vehicle that is able to climb stairs while carrying a load such as a person or an object.
2. Description of the Related Art
For example, Japanese Patent No. 4734038 describes a stair climbing vehicle including supporting portions by which four wheels are rotatably supported, a main body portion by which the supporting portions are turnably supported, and sliding mechanisms that move the supporting portions and the main body portion relative to each other in the front-rear direction. When the stair climbing vehicle climbs up stairs with a load placed on an upper face of the main body portion, the main body portion is moved while the supporting portions are turned.
Japanese Patent No. 4574016 describes a stair climbing vehicle including supporting portions by which four wheels are rotatably supported, a main body portion by which the supporting portions are turnably supported, and a load-carrying portion that is fixed to upper portions of the supporting portions and on which a person is able to be seated. When the stair climbing vehicle climbs up stairs with a person seated on the load-carrying portion, the supporting portions and the main body portion are turned relative to each other.
When each of the stair climbing vehicles described in Japanese Patent No. 4734038 and Japanese Patent No. 4574016 climbs up stairs, the main body portion oscillates back and forth about the supporting portions. Thus, the position of a load placed on the upper face of the main body portion or the position of a person seated on the load-carrying portion may be unstable.